SpringBoot基礎教程(十六)——與docker的結合

最近一段時間，容器化成為了一種趨勢。一臺伺服器可以虛擬成多個容器，同時提供服務，共享硬體資源，節約成本，容器化的翹楚就是Docker，我司的所有微服務的釋出都已經容器化。spring boot 也緊跟潮流，加入了Docker的maven外掛，可以通過執行命令來製作映象。

本節的主要內容不是講程式碼，而是講這個Docker外掛。廢話不多說，上pom

<plugin>
                <groupId>com.spotify</groupId>
                <artifactId>docker-maven-plugin</artifactId>
                <version>0.4.12</version>
                <configuration>
                    <!-- 注意imageName一定要是符合正則[a-z0-9-_.]的，否則構建不會成功 -->
                    <!-- 詳見：https://github.com/spotify/docker-maven-plugin    Invalid repository name ... only [a-z0-9-_.] are allowed-->
                    <imageName>spring-boot-docker-start</imageName>
                    <!--相當於from java,本地有使用本地的映象，沒有的話從遠端倉庫拉取-->
                    <baseImage>java</baseImage>
                    <exposes>
                        <!--暴露容器內的8080埠-->
                        <expose>8080</expose>
                    </exposes>
                    <!--進入點，執行的命令-->
                    <entryPoint>["java", "-jar", "/${project.build.finalName}.jar"]</entryPoint>
                    <resources>
                        <resource>
                            <targetPath>/</targetPath>
                            <directory>${project.build.directory}</directory>
                            <include>${project.build.finalName}.jar</include>
                        </resource>
                    </resources>
                </configuration>
            </plugin>

imageName就是映象的名稱。baseImage是基礎映象，本地有使用本地的映象，沒有的話從遠端倉庫拉取，暴露容器內的8080埠，執行java -jar 命令，啟動微服務。我們知道使用Docker需要制定Dockerfile檔案，裡面的元素完全通過maven外掛的標籤來體現了。還是有前提的，你得先安裝好Docker。講解到這裡，我們開始執行
第一步：執行mvn clean package docker:build建立生成映象。
第二步：啟動映象docker run -it -P spring-boot-docker-start,看下容器內的日誌

➜  spring-boot-docker-start git:(master) docker run -it -P spring-boot-docker-start

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v1.3.5.RELEASE)

2018-03-25 08:41:56.274  INFO 1 --- [           main] com.shuqi.ApplicationMain                : Starting ApplicationMain on 075543f8f5b6 with PID 1 (/spring-boot-docker-start.jar started by root in /)
2018-03-25 08:41:56.287  INFO 1 --- [           main] com.shuqi.ApplicationMain                : No active profile set, falling back to default profiles: default
2018-03-25 08:41:56.406  INFO 1 --- [           main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@126d28d3: startup date [Sun Mar 25 08:41:56 UTC 2018]; root of context hierarchy
2018-03-25 08:41:58.356  INFO 1 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat initialized with port(s): 8080 (http)
2018-03-25 08:41:58.382  INFO 1 --- [           main] o.apache.catalina.core.StandardService   : Starting service Tomcat
2018-03-25 08:41:58.384  INFO 1 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet Engine: Apache Tomcat/8.0.33
2018-03-25 08:41:58.512  INFO 1 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2018-03-25 08:41:58.512  INFO 1 --- [ost-startStop-1] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 2113 ms
2018-03-25 08:41:58.920  INFO 1 --- [ost-startStop-1] o.s.b.c.e.ServletRegistrationBean        : Mapping servlet: 'dispatcherServlet' to [/]
2018-03-25 08:41:58.928  INFO 1 --- [ost-startStop-1] o.s.b.c.embedded.FilterRegistrationBean  : Mapping filter: 'characterEncodingFilter' to: [/*]
2018-03-25 08:41:58.937  INFO 1 --- [ost-startStop-1] o.s.b.c.embedded.FilterRegistrationBean  : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
2018-03-25 08:41:58.937  INFO 1 --- [ost-startStop-1] o.s.b.c.embedded.FilterRegistrationBean  : Mapping filter: 'httpPutFormContentFilter' to: [/*]
2018-03-25 08:41:58.938  INFO 1 --- [ost-startStop-1] o.s.b.c.embedded.FilterRegistrationBean  : Mapping filter: 'requestContextFilter' to: [/*]
2018-03-25 08:41:59.406  INFO 1 --- [           main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@126d28d3: startup date [Sun Mar 25 08:41:56 UTC 2018]; root of context hierarchy
2018-03-25 08:41:59.516  INFO 1 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/hello],methods=[GET]}" onto public java.lang.String com.shuqi.controller.HelloController.hello()
2018-03-25 08:41:59.523  INFO 1 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error],produces=[text/html]}" onto public org.springframework.web.servlet.ModelAndView org.springframework.boot.autoconfigure.web.BasicErrorController.errorHtml(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse)
2018-03-25 08:41:59.524  INFO 1 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error]}" onto public org.springframework.http.ResponseEntity<java.util.Map<java.lang.String, java.lang.Object>> org.springframework.boot.autoconfigure.web.BasicErrorController.error(javax.servlet.http.HttpServletRequest)
2018-03-25 08:41:59.584  INFO 1 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2018-03-25 08:41:59.585  INFO 1 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2018-03-25 08:41:59.645  INFO 1 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2018-03-25 08:41:59.754  INFO 1 --- [           main] o.s.j.e.a.AnnotationMBeanExporter        : Registering beans for JMX exposure on startup
2018-03-25 08:41:59.834  INFO 1 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat started on port(s): 8080 (http)
2018-03-25 08:41:59.838  INFO 1 --- [           main] com.shuqi.ApplicationMain                : Started ApplicationMain in 4.084 seconds (JVM running for 5.012)
[2018-03-25 08:41:59] server started!

啟動成功。
第三步：輸入docker ps看看容器內的8080埠被對映到了本機的哪個埠

CONTAINER ID        IMAGE                      COMMAND                  CREATED              STATUS              PORTS                     NAMES
075543f8f5b6        spring-boot-docker-start   "java -jar /spring..."   About a minute ago   Up About a minute   0.0.0.0:32768->8080/tcp   trusting_noether

確定是32768埠。
第四步：瀏覽器中輸入http://localhost:32768/hello,看到結果

說明我們訪問容器內的程式成功了！

下節將的內容是：SpringBoot基礎教程(十七)——與日誌的結合

本節專案原始碼